Manuja, SandeepDOGRA, NIKHIL2021-03-022021-03-022020-11https://krishikosh.egranth.ac.in/handle/1/5810161864A field experiment was undertaken during kharif 2019 at the Experimental Farm of Department of Agronomy, CSK Himachal Pradesh Krishi Vishwavidyalaya, Palampur (H.P.) with the objective of standardizing fertilizer requirements for rice hybrids under mid hills of Himachal Pradesh. The experiment consisted of twenty treatment combinations which included five fertility levels viz., 50% recommended dose of fertilizer (RDF), 100 % RDF (90:40:40), 150% RDF, 150% RDF + ZnSO4 @ 25 kg ha-1 and natural farming and four varieties namely Arize 6129, Arize Swift. AZ 6508 and HPR 2143, which were tested in split plot design with fertility levels in main plot and varieties in sub plot. The soil of the experimental site was silty clay loam in texture, acidic in reaction and medium in available nitrogen, phosphorus and potassium and zinc. The results obtained from the present investigation clearly indicated the significant influence of fertility levels and varieties on the growth, development, yield attributes and yield of rice. Application of 150% RDF + ZnSO4 gave significantly higher values for almost all the yield attributes viz. number of effective tillers (213.6), filled grains per panicle (157.6) and 1000-grain weight (26.25) which ultimately resulted in significantly higher grain (63.67 q ha-1) and straw yield (74.80 q ha-1) of rice. This treatment also proved to be the most remunerative one giving higher gross return (Rs 1,34,268 ha-1), net return (Rs 87,234 ha-1) and B:C ratio (1.85). Adoption of natural farming practices gave significantly lower yield as well as returns. Application of higher dose of fertilizers also increased the nitrogen, phosphorus and potassium content in both grain and straw resulting in their higher uptake. Addition of zinc to the crop increased the zinc content in both rice grain and straw. Higher dose of fertilizers also helped maintain the fertility status of soil which declined in natural farming as well as in treatments where lower dose was added to the crop. All the hybrids tested in this investigation significantly out yielded the inbred check variety HPR 2143. Amongst the hybrids AZ 6508 gave better results in term of grain (59.9 q ha-1) and straw yield (71.8 q ha-1), gross return (Rs 1,26,703 q ha-1), net return (Rs 81,668 q ha-1) and B:C ratio (1.81). Thus, farmers of mid hills of Himachal Pradesh can increase the rice productivity by growing hybrids as well as applying higher fertilizer dose to these hybrids. Application of zinc can further increase the yield of rice as well as zinc content in rice grain and can be used to alleviate the zinc deficiency in rice eating population of our country.EnglishThesis